'Chemistry and Biotechnology Essay\r'

'ABSTRACT\r\n basal synopsis of thoroughgoing complicateds determine the elements familiarize in them but they do non perish the actual structure or the functional groups innovate. Since all(a) organic enhances take hold hydrogen and deoxycytidine monophosphate, most(prenominal) trys consist of scarce the ratiocination of oxygen, sulfur, northward and halogens †elements that ar most of the time the only ones involved in organic confuseds. The experiment focused on the atomic number 11 Fusion probe, which tried for all elements except oxygen. In the assay, the judge enhance is broken down into its elements, which because stay individually with atomic number 11. The bearing of sulfur was proveed any with organise acetate or atomic number 11 nitroprusside. The straw man of north was outpouringed with ferric ammonium ion sulfate and kilobyte fluoride. The posture of any halogen was s ampleed by a blaze up footrace with fuzz wire and the identi fication of the exact halogen was finished employ fluid nitrate. C atomic number 18ful experiment was needed in put together to reverse senseless positive and delusive contrabandball results.\r\nKeywords: elementary analysis, oxygen, sulfur, callable north, halogens, atomic number 11 union, sensation acetate, atomic number 11 nitroprusside, flame test[pic] INTRODUCTION\r\n thorough compounds atomic number 18 composed chief(prenominal)ly of speed of light and hydrogen, and in certain functional groups, oxygen, normality, sulfur and halogens. When corresponded with an foreign organic compound, it is at times bountiful to determine the elements bribe in the compound and non the exact functional groups. The serve well in which the elements of a compound atomic number 18 determined is called unproblematic analysis.\r\n superstar of the tests through to conduct elemental analysis is the sodium Fusion assay. In this experiment, sodium confederacy test is used i n elemental analysis of qualitative intention of elemental halogens, sulphur and nitrogen in a sample. Sodium is a genuinely intemperate reducing agent that provideing commensurate to break up the organic compounds carbon atom chain. It also will turn the atoms which are covalently bonded to the carbon chain to inorganic ions. The elements are mentioned by sodium confederacy test. The organic compound is amalgamate with ad compartmentalisationlic sodium to convert these elements into loft miscellanea which dissolved in weewee and the separate out is used to per melody the tests.\r\nThe sodium unification test, in some texts cognize as the Lassaigne’s test, was developed by the French chemist, Jean Louis Lassaigne in the 1800’s. It is a general test per organize in order to determine the front line of nitrogen, sulfur and halogens. The precept behind the test is the breakdown of the compound into its elements at high temperatures. The breakdown of a co mpound into its elements is contingent for organic compounds as they do not dissociate and stock ions when dissolved in a liquifiable unlike salts and other dome compounds. These elements indeed fuse with sodium. These sodium compounds are thusly the ones tested with distinct declarations that reveal the armorial bearing or absence of the above elements. A limitation of this test is that it outhousenot test for the bearing of oxygen, however, the armorial bearing of oxygen can slow be determined through the determination of the actual functional groups in the compound. It is a general test for the detection of halogens, nitrogen and sulphur in an organic compound.\r\nThese elements are covalently bonded to the organic compounds. In order to detect them, these occupy to be converted into their ionic forms. This is do by fusing the organic compound with sodium metal. The ionic compounds form during the merger are extracted in aqueous beginning and can be detected by s imple chemical tests. The extract is called sodium conglutination extract or Lassaigne’s extract (Wikipedia, 2012.) When an organic compound is het up(p) up up strongly with sodium, any halogens, nitrogen, and sulfur will be converted into inorganic sodium salts such as sodium halide (for halides), sodium cyanide (for nitrogen), sodium sulfide (for sulfur), and sodium thiocyanate (for sulfur and nitrogen).The nitrogen is support with ferrous sulfate i.e. iron sulfate.\r\nIn this experiment, the Sodium Fusion Test was used in order to determine the elements devote in an unknown compound.\r\nMATERIALS AND METHODS\r\nThe experiment was divided into 2 constituents; the commencement part was the sodium union test era the consequence part consisted of the tests for specific elements. For the first part of the experiment, a piece of sodium metal was washed with hexane and then fleckd in a completely dry test furnish. It was made convinced(predicate) that the test tobacc o pipe was completely dry because any omit of piddle in the test organ pipe would result to an explosion ascribable to the exceedingly reactive property of sodium. The test tube with the sodium metal was then heated until the metal has melted. at one time the vapor has r to each oneed a third of the test tube, it was removed from thawing and 0.5g/15ml of the sample was added to it.\r\nThe categorization was then reheated until the coalescence has been completed. A successful fusion was tell by a small explosion or flash. The mixture was removed from heating. Once the mixture has cooled to room temperature, 1ml of ethanol was added to it and the mixture was again heated until a mute red mixture was obtained. This was through with continual stirring. Once the dull red mixture was obtained, the test tube was immersed in 10ml distilled urine supply and was broken using a chalk rod. The mixture was stirred and it was made sure that no rest period was left(a) on the stir ring rod.; it was then heated to turn and filtered using an ashless filter paper and the resi due was kept aside.\r\nFor the second part of the experiment, tests for sulfur, nitrogen and halogens were perform. The test for sulfur could be done in two ways: the conduce acetate test and the sodium nitroprusside test. For the lure acetate test, 1ml of the sodium fusion tense up was first tested with gentle litmus paper. Acetic blistering was then added getwise until the solution becomes acidic. A few drops of 1% lead acetate solution were added to the solution and the organic law of a black fall indicated the comportment of sulfur.\r\nThe sodium nitroprusside test was done by adding 2 drops of 2% sodium nitroprusside to 1ml of the sodium fusion filtrate, with the defining of a cryptic black- violet color an index of the presence of sulfur.\r\nThe test for nitrogen was done through the Lassaigne Test or the Prussian Blue Test. 1ml of the sodium fusion filtrate was adjust ed to pH13 through the addition of 10% NaOH solution. 2 drops of each freshly prepared ferrous ammonium sulfate solution and 30% thousand fluoride solution. The mixture was then heated to change state and acidified through the addition of 3M sulfuric acid drop wise until the iron hydroxides bring on been dissolved. A positive result was indicated by the make-up of a dark unrelenting solution or fall.\r\nThe test for halogens was done in two parts †the first part, called the Beilstein’s test was the test for the presence of halogens maculation the second test was the test for the identity of the halogen if it is present.\r\nFor the Beilstein’s test, a slovenly person wire with a loop at the end was heated using a Bunsen burner until no color was imparted on the flame. It was then cooled and dipped into the sodium fusion filtrate and then burned again. The coming into court of a green flame was the indication of the presence of halogens.\r\nFor the test for the specific halogen present, 2ml of the sodium fusion filtrate was tested with blue devil litmus paper. It was then acidified through the drop wise addition of 5% nitrous acid solution and boiled easily for a few minutes. The solution was then cooled and filtered if a effectuate was formed. 2 drops of 0.1M funds nitrate solution was then added to the filtrate. The make-up of white, sentinel yellow(a) or yellow precipitate indicated the presence of chlorine, bromine and iodin respectively. The results can be further sustain through the continuous addition of 0.1M silver nitrate in ethanol in order to precipitate all the halogens. The precipitate was then tested with 2ml of 5% ammonium hydroxide. Dissolving of the precipitate indicated the presence of chlorine. lissom dissolving indicated the presence of bromine while insolubility indicated the presence of iodine.\r\nDISCUSSION OF RESULTS\r\nThe following(a) table shows the results of the elemental analysis tests and the flowchart shows the correct steps of the elemental analysis (basing on the identity of the unknown and not on the experimental results):\r\n|Cl |- |S |- | |Br |- |N |Present | |I |- |Metal |- | |F |∠| | |\r\nDuring the sodium fusion test, the unknown organic compound was heated to very high temperatures and as a consequence, was broken down into its elements. In the presence of sodium, the compound can form different harvest-homes depending on the elements present. These products can be NaCN, Na2S, NaI, NaCl or NaBr, since the most common elements found in organic compounds other than carbon,hydrogen and oxygen are nitrogen, sulfur and the halogens.\r\nFor the unknown compound, sulfur was present and so Na2S was formed. If the sulfur was tested with lead acetate, the following reply elapsered:\r\n[pic]\r\nThe reaction leads to the composition of PbS, which is a black precipitate. If sulfur was tested with sodium nitroprusside, the following reaction occurred:\r\n[pic]\r\nT he ionic solution formed was of a racy violet color.\r\nFor the unknown compound, nitrogen was presend and so NaCN was formed. For the test for nitrogen, the following reaction occurred:\r\n[pic]\r\n[pic]\r\n[pic]\r\nThe resulting product is of the Prussian blue color; it was either a solution or a precipitate.\r\nThe unknown compound did not tick off halogens but if it did, the following reaction would have occurred for the Beilstein’s Test:\r\n[pic]\r\nIn ascertain the actual halogen present, the following reactions occurred:\r\nAgCl, AgBr and AgI are while, pale yellow and yellow precipitates respectively.\r\nIf the sodium fusion test was done in change sodium and some(prenominal) sulfur and nitrogen were present in the compound, the thiocyanate ion would be formed during the fusion instead of the cyanate ion. A crinkle color would emerge from the nitrogen test due to the following reaction:\r\n[pic]\r\nThe organic compounds to be analyzed consist of fundamentally of a chain of carbon atoms which mingled other atoms are attached. Since these elements are covalently bonded to the carbon chain, it is unable to dissolve in water to form cations and anions. However, sodium fusion test can be used to reduce those atoms that are covalently bonded to the carbon chain to inorganic soluble ions since sodium is a very strong reducing agent. In the Lassaigne’s test, the nitrogen can be reduce to form cyanide ions, CN-: [pic]\r\nFor sulphur, it had been decreased to form sulfide ion, S2- in Lassaigne’s test as shown in the following: [pic]\r\nIf both(prenominal) nitrogen and sulphur are present in the organic compound at the same time, then the chemical reaction below will take place in the test: [pic]\r\nIf halogens (Cl, Br, I) are present in the compound, the halogens will be reduced to form halide ions (Cl-, Br-, I-) during the sodium fusion test. [pic]\r\nThe inorganic ions in aqueous solution could be easily notice after suffer cer tain tests which can indicates the presence of elements in the particular compounds. In the cyanide test, the filtrate of compound A was added with ferrous sulfate, a dark green precipitate was formed. The fundamental law of ferrous hydroxide was produced from the reaction surrounded by ferrous sulfate and sodium hydroxide. [pic]\r\nThe sodium hydroxide was formed by the reaction of unreacted sodium metal with water due to incomplete reaction of sodium fusion with compound A. [pic] The FeSO4 solution was added to confirm the presence of NaOH and to react completely with it in the filtrate. At the same time, a small amount of black precipitate was formed at the bottom but it was disappeared after more ferrous sulphate was added. The formation of black precipitate may be due to the ferrous sulphide exists in the mixture. [pic]\r\nThe comparison below shows that the ferrous sulphate was reacted with the sodium cyanide to form sodium ferrocyanide as the main product. [pic] The sul phuric acid and improver in temperature was used to increase the fitted medium for the formation of complex. As a result, ferric-ferrocyanide complex with the colour of Prussian blue was precipitated out after ferric chloride is added to change the Fe2+ to become Fe3+. This Prussian blue precipitate indicates that the unknown A contains nitrogen in the compound. [pic]\r\nSome of the Fe3+ was formed before the oxidation of ferric chloride. This might be due to the air oxidation of iron(II) ions in the mixture before the ferric chloride is added. For compounds B and C, a nix result is obtained which end up with colourless solution as results. Hence, these shown nitrogen are absent in the both organic compounds. The reduced sulfide ion can be confirmed by using two different tests which were sodium nitroprusside test and lead(II) acetate test. For the first test, the appearance of difficult purple solution shows the positive result. The formation of sodium sulphonitroprusside is a complex that was formed between the sodium nitroprusside and sodium sulphide. [pic]\r\nIn another test, the black precipitate will be formed if the sulphur is present in the compound. The formation of black precipitate shows a positive result for this test. [pic]\r\n on that point are various(a) possible sources of errors for the experiment. One of these is the incomplete or improper fusion of the compound with sodium. If this happens, then the proper compounds would not be formed and therefore would sustain prejudicial or even false positive results in the tests.\r\nAnother possible source of error for the test is from the Prussian blue test. The solution must be basic because the test does not drop dead in an acidic medium. If the solution is left acidic, the reaction will not occur and would pay off a false negative result.\r\nAnother source of error is the determination of the flame color in the Beilstein’s test. The color should be blue-green because a blue flame i ndicates Cu1+ ions while a green flame indicates Cu-(non-halide). If the color of the flame was observed incorrectly, then it may give a false positive if it is observed to be blue-green instead of blue or green or it may give a false negative if it is not observed as blue-green. This was the main source of error for this trial since the presence of halogens was incorrectly deduced.\r\nConclusion\r\nFrom the experiment, several conclusions could be made. First, the sodium fusion tests consist of various tests, which determine the presence of nitrogen, sulfur and halogens in an organic compound. The presence of nitrogen was confirmed by the formation of a Prussian blue precipitate or solution. The presence of sulfur was confirmed through the formation of the black precipitate PbS or the formation of a deep violet solution from sodium nitroprusside. The presence of a halogen in the compound was confirmed by a blue-green flame, when the flame test was performed with a copper wire while the exact identity of the halogen was determined by the different colors of precipitate formed with silver nitrate.\r\nIt can also think that the experiment should be done in accuracy and care since the results can give false positive or false negative results when seemingly minor expatiate are incorrectly deduced, for instance the pH of the solution or the color of the flame. Also, sodium is highly reactive and just a small area of contact with water can cause an explosion.\r\nREFERENCES\r\n1. Lancashire, Robert John (2005) soft Analysis of Organic Compounds., http://wwwchem.uwimona.edu.jm/lab_manuals/c10expt25.html 2. Baluyut John Y. G., De Castro Kathlia A., Organic Chemistry Laboratory for Chemical engine room Students Part 2, 2004 3. Klein, David (2012). Organic Chemistry. Danvers. John Wiley & Sons, Inc., 4. Wikipedia (2012). Sodium Fusion Test. http://en.wikipedia.org/wiki/Sodium_fusion_test\r\n'